Taking it to the Next Level
Innovative Nutrient Management Kindles Yield Breakthroughs
By Laura Temple
A growing number of Illinois farmers manage soybean and corn fertilizer completely separately. And new technologies not only make it easier, they can boost return on investment (ROI).
“The trend of fertilizing crops separately has been growing annually for several years,” confirms John Watkins, Certified Crop Adviser (CCA) and marketing manager for Nutrien in Cerro Gordo, Illinois. “Research and a growing understanding of the science of crop production is showing the value of spreading plant nutrition throughout the growing season.”
That can include up to 18 essential nutrients. Former ISA CCA Envoy David Rahe noted via ILSoyAdvisor last season that nitrogen, phosphorus and potassium are the most likely to be added as fertilizer. “Water, carbon and oxygen come from air and water. Calcium, magnesium and sulfur are needed in large amounts as well, and in Illinois we generally take what we get from nature,” he noted.
Watkins shares a variety of innovations that can increase fertilizer efficiency, soil health and yield. “Plant nutrition has transformed from a snake oil market 10 year ago, where we threw products into plants hoping for a response, to one based in true science,” Watkins says. “Today it’s all based in plant and soil science that can be explained.”
According to Watkins, farmers typically choose a few nutrient options that best fit their system and budget. “The ROI is usually about three-to-one on many of the technologies.”
Biochemical Fertilizer Catalysts
Though soybeans fix nitrogen, they need phosphorus and potassium. Farmers often apply those nutrients as dry fertilizer – DAP (diammonium phosphate) and potash – in fall or early spring. The most recent numbers from the University of Illinois to estimate nutrient removal in the state are 0.75 lbs. of phosphorus and 1.17 lbs. of potassium per bushel of soybeans.
“Dry fertilizer is very inefficient,” Watkins says. “Only 10 to 30 percent of phosphorus is available to the crop in the first year. The range for potassium is 20 to 60 percent availability.”
To improve efficacy and nutrient availability, many companies treat dry fertilizers with biochemical fertilizer catalysts. “These additives mimic biological agents found in the soil to enhance fertilizer breakdown and increase nutrient availability by 15 to 20 percent,” he says. “They also improve availability of existing nutrients in the soil.”
Quick Tissue Analysis
“Feeding soybeans throughout the season is key to pushing yield and improving crop management,” Watkins says. “It also helps farmers adapt to the growing season.”
He believes the availability of quick, cost-effective tissue analysis will grow in-season nutrition applications. It pinpoints nutrient issues to address based on weather, yield potential and markets.
“Farmers or their agronomists can start taking samples from V2 through V6 stages and get results in 48 hours to know what the crop needs,” he says, noting analysis costs $10 to $12 per sample. A sample can account for about 20 acres, allowing for zone treatment of any deficiency.
Rahe noted a few cautions concerning tissue testing:
- Time of day sampled can make a difference.
- Sometimes dust on the plant can skew results.
- Don’t test when the crop is stressed.
Watkins says micronutrients are often the cheapest way to fix a variety of problems. Soybeans may experience deficiencies in boron, iron, manganese, sulfur or zinc. Adding them to nutrition programs addresses microbe and plant health problems. Options exist to add micronutrients to any application, from dry fertilizer through post-emergence herbicide and fungicide applications.
“The first step in getting your micronutrient levels in order is to get your soil pH right. Soil pH affects the availability of all plant nutrients, but in order to keep micronutrients available, pH needs to be in the sweet spot between 6.0 and 7.0,” Rahe wrote.
Late in the season, soybeans may also need additional macronutrients.
“For example, 80 bushel-per-acre soybeans need 275 pounds of nitrogen, which is actually more than corn,” he says. “They fix most of that themselves. But late in the season, nodulation slows, and plants may need help to get the nitrogen – or even potassium – needed to fill pods.”
Plant Growth Regulators
“Plant growth regulators (PGRs) are part of fertility,” asserts Watkins. “They increase early season vigor, support root and shoot growth and reduce early season stress.”
He explains that plants use their root hairs to take in two-thirds of their nutrients, but that individual root hairs last just five to seven days before they damp off. Roots need to keep growing to ensure plants can take up nutrients as needed.
“Many PGRs actually work by supporting soil health. They feed soil microbes,” he says. “For example, one teaspoon of soil contains 50 billion microbes, and we have only identified one percent of them. We are learning more about what they need and how they impact crops, and this area could provide the next big yield breakthrough.”
PGRs can be applied with seed treatments or post-emergence herbicide applications, with flexibility similar to other nutrients. Carrier systems developed for all of these products get them to where plants need them, one reason Watkins believes current nutritionals are more effective.
Understanding nutrient delivery at the molecular and atomic levels also improves fertilizer efficiency, regardless of application timing.
“Using nanotechnology to deliver plant nutrients has the potential to improve fertilizer and nutrient efficacy,” says Landon Bunderson, Ph.D., and chief science officer for Aqua-Yield, an ag nanotechnology company. Though one nanometer is one billionth of a meter, nanoparticles have mass that matter in solution and can better penetrate plants instead of getting washed away.
“Our technology attracts and loads the chemical ions and molecules in inputs like fertilizer into nanoparticles,” he explains. “Particles in solution typically move into plants through channels that plant cells regulate like border control. Larger nanoparticles can circumvent typical channels because they may be treated like a foreign body. They are pulled into the plant and quickly broken down, releasing a high concentration of nutrients more efficiently.”
Bunderson cites research demonstrating value of nanotechnology as a fertilizer delivery system. In a North Dakota soybean trial, using nanotechnology to deliver micronutrients increased content of iron, manganese, boron, copper and zinc in plant leaves. Trials in other crops show fertilizer rates can be reduced 20 to 25 percent or more, while still delivering target yield.
Like other technologies, Aqua-Yield’s delivery system has just become available in recent years. The company expects use to increase as farmers learn its value to nutrient management plans.
Precision Application Technology
Precision application of all of these technologies would add even another layer of efficiency, and Watkins expects to see more of that in the future as it becomes possible.
For many of these nutrient technologies to deliver a high ROI, they are applied with other products or during other field operations. But equipment is not yet available to allow variable rate applications of multiple inputs – with different prescriptions – at the same time.
These innovations and more are here or on the horizon and gaining traction. Together, they could allow farmers to grow more profitable, high-quality soybeans with more efficient input use.